1. Field of the Invention
This invention relates to towing apparatus and, more particularly, to novel systems and methods for securing trailers to towing vehicles with hitches.
2. The Background Art
Trailers have been towed since the earliest days of the wheel. A cart or wagon towed behind an animal is a trailer. In modern times, trailers are secured to towing vehicles by a multiplicity of methods, including frame-mounted hitches and bumper-mounted hitches. Tractor-trailer rigs often use pintle-type fifth-wheel towing systems. Similarly, recreational vehicles sometimes use fifth-wheel towing systems or often a receiver-type mounted ball hitch.
A receiver hitch relies on a receiver cavity or tube securely mounted to the frame or undercarriage of a towing vehicle. The receiver may be reinforced and is provided with an aperture for receiving a trunnion. A trunnion may be secured into the receiver by a lock, such as a pin. On the trunnion may be mounted a hitch. The hitch may be a pintle hitch or ball hitch, typically, but need not be limited thereto.
Pintle style hitches are typically complicated mechanisms and make use of parts having complex geometries. Pintle hitches also generally have complex locking mechanisms that have limited functionality, locking only in one position.
Typical pintle hitches are bulky and must remain in a deployed position. Accordingly it would be an advancement in the art to provide a pintle hitch system that is stowable while remaining connected to a vehicle. It would also be an advancement in the art to provide a pintle hitch providing this functionality while at the same time having a simple design making it easy to manufacture. Providing a simpler design would also make such a pintle hitch easier and safer to use and less prone to failure.
Typical hitch systems are designed for towing trailers over substantially smooth roads. There is typically little accommodation for twisting of the trailer relative to the towing vehicle. Thus, it would be an advancement in the art to provide a towing system that was able to accommodate such twisting motion. Such a system would facilitate the towing of trailers and the like over rugged terrain.
An apparatus is disclosed in sufficient detail to enable one of ordinary skill in the art to make and use the invention. In certain embodiments an apparatus in accordance with the invention may have a trunnion for insertion into a receiver tube or cavity of a vehicle. A base may be secured to the trunnion or to the vehicle. The base may also have a mount secured thereto. The mount may have a platform that is sized and positioned to receive a hitch.
Various details of bases, mounts, and the like are discussed in U.S. patent application Ser. No. 09/559,603 filed Apr. 27, 2000 and entitled STOWAWAY RECEIVER HITCH, now U.S. Pat. No. 6,460,870, issued Oct. 8, 2002; U.S. patent application Ser. No. 09/699,279 filed Oct. 26, 2000 and entitled PIVOTING, UNDERSLUNG, STOWAWAY, HITCH MOUNT, now U.S. Pat. 6,712,381, issued Mar. 30, 2004; and U.S. patent application Ser. No. 10/078,322 filed Feb. 12, 2002 and entitled MONOLITHIC DOUBLE-BALL HITCH incorporated herein by reference.
The mount may also have a retainer that may be moved into position and locked in order to prevent removal of a pintle ring from around the hitch. The retainer may be mounted on a pivot allowing it to rotate into and out of position. It may also be mounted on a guide such that it may translate relative to the mount. Through rotation and translation, the retainer may be moved to positions suitable for temporarily holding the retainer and for locking the retainer into position. The pivot and guide may be positioned such that the retainer can not be both rotated and translated at the same time. For example, the retainer may be rotated about the pivot and translated into a position where rotation is substantially impossible. This may allow the retainer to be placed out of the way so that a pintle ring can be brought down over the hitch. Likewise the retainer may be brought into a position where it is only possible to rotate the hitch about the pivot. The retainer may be of very simple construction such as a substantially flat plate in which needed apertures and outlines are formed.
A stop on the platform may engage a surface on a hitch and prevent it from rotating. This may facilitate installation of a hitch. For example, the stop engaging the hitch may enable a user to use a single wrench to tighten down a nut holding the hitch to the platform. The stop could be as simple as a shoulder or flat formed in the platform.
The mount may be adjustable relative to the base. The apparatus may have another guide to enable the mount to translate relative to the base. This may allow the mount to be height-adjustable and provide versatility of operation. The mount and base may also be secured to one another by a pivot allowing the mount to rotate into a variety of positions. This may enable the mount to be secured in an unobtrusive stowed position.
Locks may be used to fix the position of the retainer relative to the mount and the position of the mount relative to the base. In some embodiments the locks may be locking pins extending through apertures formed in both of the members, thus fixing the members relative to one another.
The base may have a height index that receives the locks so that the mount may be secured at a variety of positions relative to the base. In some embodiments the height index may be a series of apertures formed in the base and sized to receive the locking pins.